Currently, acoustic devices such as microphones are geometrically symmetric with little internal structure. They consist of rectangular or circular plates whose motions are detected capacitively, piezoelectrically, or piezoresistively. In its operating frequency range, mechanical response of such a device is a relatively smooth function of frequency. For more complex transfer functions, electronic filters must be used.
Micromachining, on the other hand, allows the fabrication of reproducible microstructures that have complex mechanical transfer functions. Complicating the mechanical designs simplifies the electronics which, in turn, can reduce required power and increase signal-to-noise ratio. This concept may improve performance of hearing aids. Tools such as finite-element methods may be used to predict and tailor the response of a given device.
An object of the present invention is to provide a micromachined acoustic source and receiver.
Another object of the present invention is to provide a micromachined acoustic source that may be used as a microcutter, microchisel or microhammer.
Yet another object of the present invention is to provide a micromachined structure that may function as a micro-optical component in application of optical phase modulation and beam chopping.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the claims.